a Few Questions About Getting On the Pill...

I've never been on birth control before. Never had sex, either. But most probably will this January 2008 (in a long distance relationship). But before I do, I want to make sure I'm fully protected. But there are a few questions I have...

1. I'm planning on going to Planned Parenthood for my examination and pills. Has anyone had any good or bad experiences there?

2. I'm quite overweight. I got to a point where I was so overweight that my periods stopped completely but I've had my last two periods (I've been losing weight). Do you think the pill would be ineffective for someone who is quite over weight? Or if the doctor will even prescribe the pill to someone like me?

3. I've read that one should take the pill for at least 7 days for it to be protective against pregnancy. Other places, I've read you need to take it for three months to be effective as a contraceptive. I plan on taking it after my first period in November.

Um... sorry if I sound utterly clueless. But I did a bit of research and figured a response from a forum full of people would be more helpful. Just so I know what to expect when I go to the doctor.